# 动物类
class Animal:
    def call(self):
        print('动物叫')

class Dog(Animal):
    def call(self):
        print('汪汪')

class Cat(Animal):
    def call(self):
        print('喵喵')

# 传统调用
dog = Dog()
cat = Cat()

dog.call()
cat.call()

# 定义统一接口调用
def do_call(obj):
    obj.call()

# 其他语言
# def do_call(obj Animal):
#     obj.call()


do_call(Dog())
do_call(Cat())
